Raymarine autopilot upgrade, old as reserve?

[davethedog]

Hello all,

We currently have a Raymarine S3 course computer, fluxgate compass, type 1 drive and ST6001 head unit, all linked to a SEATALK network and then to a Raymarine Axiom Pro MFD (which does not control the autopilot as it is too old).

All is working fine BUT as we are looking to build in some redundancy to the system (as we sail short handed just the 2 of us a lot, and I may be going single handed for an offshore trip) thinking of adding a new Raymarine EVO system (compass, head unit, computer and drive unit) and then keeping the ST6001 system in place as a reserve system if needed.

So the questions are:

1. Is the new EVO autopilot much better than what we currently have?
2. Is my thinking logical (reserve autopilot and new system integrated to MFD fully)?

A lot of cash to spend but thinking of redundancy options if the current AP goes down...

DTD

 

[Yngmar]

1. If your old S3 didn't have the then optional gyro add-on, yes, the Evo will be considerably better just because the set comes with one by default. If not, it should still be notably better, as the Evo is a bit smarter with determining the best settings automatically, while the S3/Autohelm needs more manual parameter tweaking to perform well, especially with changing sea state.

2. Yes, IMHO the only sensible redundancy is a full stand-by system ready to take over at the push of a button (or two). I think it's well worth having if you rely on the autopilot a lot, as most single-handers and long distance cruisers do. It does however mean you have two drive units attached the the steering system, so you can't re-use the mounts for the old and new mounts for the additional drive must be added to the boat. That may add significant extra labour.

Also you may want to make sure only one of them can be switched on at a time, or at least point this out with warning labels. If both drives engage at the same time, the steering movements will not be perfectly matched and the powerful drives working against each other will wreak serious havoc.

 

[davethedog]

Thanks and doing some thinking as the plan would be to have the 2 systems totally separate, using the newly purchased EVO system as the primary one.

 

[dom]

So the questions are:

1. Is the new EVO autopilot much better than what we currently have?
2. Is my thinking logical (reserve autopilot and new system integrated to MFD fully)?

A lot of cash to spend but thinking of redundancy options if the current AP goes down...

Hi Dave, Yes the Evo will be much better no matter what upgrades your current system has, as a consequence of better software and faster processing power if nothing else.

Re backup, configuration there are some decisions here. First, you will need to ensure that the backup system is fully functional with the primary system out. What this normally means is that it can only steer to a course, for which you'll need to retain the existing fluxgate compass and you'll need to be able to input speed to the backup AP manually. Unless you want to run parallel wind, depth, speed, etc., which I doubt.

Re drive: I have configured to allow both the primary and legacy systems operate the same drive. I keep a spare one for redundancy. You can fit 2x drives but that is quite a lot of hassle. You might take a decision to leave a spare drive altogether unless well offshore? (Note: you will need to retain the existing rudder reference unit for the backup AP)

Re switch over system: many roads to Rome here. I have connected 2x quality multiplugs to two AP systems, which must be physically unplugged to power down the working AP processor and its drive interface and then reconnected to the backup system. Avoids any possibility of a clash and takes less than 1m to do.

 

[prv]

I changed from an S1 to Evo and noticed much better steering. The new system has a multi-axis accelerometer rather than just a simple compass, plus a couple of decades' improvement in processing power and sophistication.

While an instant switchover to a complete end-to-end standby system would be nice, as others have said the installation of two drives might not be worth it. I also wonder about the additional drag. Probably sufficient to have a single drive installed, another on board as a spare in case it's the drive that fails, and a two-pole break-before-make changeover switch that allows the drive to be connected to either pilot system. Put a plug and socket in the drive wiring so you can swap the new one in quickly.

Pete

 

[LadyInBed]

You can get the EVO with a Type 1 linear drive, so it will fit onto your current mounting, so no problem there.
If you have the bulkhead space for the rest of the kit then there should be no issues.

 

[davethedog]

Thanks all and going to have a serious think as the current system is working fine BUT always looking at redundancy.

The VO with type 1 drive kit may be just on the cusp of too small for our 41ft AWB, which would be typical as Raymarine do not seem to do a kit with the type 2 linear drive do they?

 

[RupertW]

Your modern replacement sounds ideal but expensive of course. I have a S5?? course computer from 2012, with a two spare flux gate compasses (first a misdiagnoses that that was the problem not the old course computer and second came with the S5 along with a spare rudder sensor. Added to that I’ve a spare cable from the instrument head to the course computer led through and from last year a new Type 2 drive fitted with the old Type 1 (which cut out very occasionally at the end) as a spare.
So I’ve got a completely spare set apart from course computer and instrument head. Thanks to the forum I have the code for an autohelm system for a Raspberry Pi so just need to get one of those and have a play and maybe tweak the code.